I have someone wanting old tree bark mulch removed from their yard and shrub beds. The bark has been there for awhile. It's embedded into the ground and under her St. Augustine grass. I can only think of raking it, but figured it would be hours for a small section, about 4 (2)medium, (2)large areas. I'm just worried about trying to rake this stuff through the grass and some weeds, which has started to root to the bark also. What would you use, and what would you charge?